Venous Ulcers Quiz 2 Flashcards
Do deep or superficial veins have more valves?
Deep veins have more valves
Name some of the deep veins in the lower extremity
Posterior tibial vein Anterior Tibial Vein Fibular Veins Popliteal Veins Femoral Vein Deep Femoral Vein External Iliac Vein
What are the 3 types of veins in the lower leg?
Deep
Superficial
Perforator
What is another name for the superficial venous system?
Saphenous System
What are the 2 major vessels in the superficial venous system?
Greater Saphenous (longest vein in the body) Lesser Saphenous (contains 9-12 valves)
Are there more valves in the lower leg or upper leg?
Lower leg (helps fight against gravity)
What is the purpose of the perforator veins?
Connect superficial to deep veins
How many perforators are in the leg?
200 below the knee
20 above the knee
(varies greatly)
How often are incompetent venous valves in perforating and superficial vessels found in patients with venous ulcers?
50-60%
What are the 3 major mechanisms to help return blood to the heart through the venous system?
Smooth muscle tone in the vessel walls
Contraction of calf muscles
Negative intrathoracic pressure created during inspiration
What’s the most important mechanism in returning blood to the heart?
Muscle pump (pushes blood out of deep veins and into central circulation)
Are the valves open or closed when the muscle relaxes?
Open (allow blood into deep system from superficial system)
How does respiration help in blood return?
Movement of diaphragm creates a negative pressure in the chest
What is ambulatory venous hypertension?
Sustained high pressure in low pressure veins (caused by retrograde flow from incompetent valves)
What happens during ambulatory venous hypertension?
Unidirectional flow of blood becomes bidirectional
Edema builds up in the legs due to congested superficial veins
Deep veins aren’t completely emptied out creating an increased pressure
What can improper functioning of the venous system lead to?
Chronic Venous Insufficiency
What are the 2 possible mechanisms for chronic venous insufficiency?
Fibrin Cuff Theory
White Blood Cell Trapping Hypothesis
What is the fibrin cuff theory?
Venous hypertension is transmitted to the superficial veins which causes widening of the capillary pores
Allows for large macromolecules to escape into interstitial space
Edema forms in the leg
Fibrin accumulates in the dermis and causes fibrin cuff (creates hard, non-pitting edema)
What does the fibrin cuff create?
Mechanical border and lessens the delivery of oxygen and other nutrients to the skin
What is the white blood cell-trapping hypothesis?
Transient elevation in the venous pressures decrease capillary blood flow, resulting in trapping of white blood cells at the capillary level
Trapping plugs capillary loops and results in areas of localized ischemia
What is the enzymes that aid in cell death?
Proteolytic enzymes
Which area of the lower leg has frequent problems with chronic venous insufficiency?
Medial Malleolus
Great saphenous vein has greatest curvature at this region
What are some other factors that can cause venous ulcers?
Trauma to involved area
Infection
What are the clinical indicators for CVI?
Localized limb pain (decreased with elevation, increased with leg dependency) Pain with deep pressure or palpation Pedal pulses are present Increased temperature around the wound Indistinct, irregular wound edges Lower extremity edema Shallow, fibrous covered wound bed, substantial drainage Hemosiderin staining Lipoderatosclerotic changes
What are the scores you need with the wells score to predict a DVT?
> 1 indicates high probability (28% chance)
What is lipodermatosclerosis?
Results from inflammation of the subcutaneous adipose tissue
Tissues become sclerotic over time
Skin becomes thick, hard, and onctracted with the inverted champagne-bottle appearance